Multi-working-condition clutch control method for power shifting tractor

Abstract

The invention relates to a multi-working-condition clutch control method for a power shifting tractor. The multi-working-condition clutch control method comprises the following specific steps that S1, basic parameters of a wet clutch of the tractor are calibrated; s2, the starting stage of the tractor is controlled; and S3, gear shifting in the advancing process of the tractor is controlled. The method has the beneficial effects that the current gear transmission ratio and the load size of the power shifting tractor are judged according to the parameters in the starting process of the power shifting tractor, the shifting process in the advancing process is compensated, and the curve control precision and comfort of the shifting clutch in the vehicle starting and advancing process can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of tractor power shift clutch control, and in particular to a multi-operating-mode clutch control method for a power shift tractor. Background Art

[0002] There are many different operating conditions for power-shift tractors. Different operating conditions require different vehicle speeds and mechanical gear selections. The difference in transmission ratios leads to different and large differences in the torque required for the tractor's wet clutch when starting. As a result, the existing control system cannot adapt to the comfortable starting control of all gears. Installing a gear sensor in the tractor system is costly and there is no suitable installation location.

[0003] The existing power shift tractor control technology can adapt to the starting control under different engine loads with a fixed transmission ratio, but it has the disadvantage of being unable to adapt to the starting control under different transmission ratios and cannot meet the current driver's requirements for the driving comfort of power shift tractors. Summary of the invention

[0004] The invention provides a multi-operating-mode clutch control method for a power-shift tractor, aiming to solve the problems in the prior art.

[0005] The technical solution of the present invention to solve the above technical problems is as follows:

[0006] A multi-operating clutch control method for a power shift tractor comprises the following specific steps:

[0007] S1: Calibrate the basic parameters of the tractor wet clutch;

[0008] S2: Control the starting phase of the tractor;

[0009] S3: Control the gear shifting during the movement of the tractor.

[0010] The beneficial effects of the present invention are as follows: the present invention determines the current gear transmission ratio and load size of the power shift tractor according to the parameters during the starting process of the power shift tractor, compensates for the shifting process during driving, and can improve the control accuracy and comfort of the clutch curve during vehicle starting and driving.

[0011] Based on the above technical solution, the present invention can also be improved as follows.

[0012] Further, the S2 specifically includes:

[0013] S21: Controlling the power shift tractor starting process, phase A;

[0014] S22: Controlling the power shift tractor acceleration limiting phases B and C;

[0015] S23: Control the power shift tractor pressure rapid increase stage D.

[0016] The beneficial effect of adopting the above further scheme is to determine the starting gear transmission ratio range of the power-shift tractor according to the starting KP point of the adaptive power-shift tractor and the relevant parameters of the KP point adaptive stage, thereby limiting the minimum acceleration and maximum acceleration of the tractor, and achieving the maximum shortening of the clutch slip time during clutch control, thereby achieving the purpose of protecting the clutch.

[0017] Further, the S21 specifically includes:

[0018] According to the transmission parameter calculation, the oil pressure is increased by 1.5 bar every 890ms, and the vehicle speed signal is monitored. When the vehicle speed exceeds the set threshold, it jumps to stage B.

[0019] The beneficial effects of adopting the above-mentioned further scheme are that the method is simple, the design is reasonable, it can adapt to the vehicle gear and load, and it can estimate the vehicle load size based on process data to provide effective data for the subsequent control stage. On the premise of improving vehicle driving comfort, it achieves the goal of shortening the clutch slip time to the maximum extent during clutch control, thereby achieving the purpose of protecting the clutch.

[0020] Further, the S22 specifically includes:

[0021] Stage B is the acceleration stage, in which the control pressure increases rapidly to reach the minimum acceleration;

[0022] Phase C actively reduces the rate of pressure increase while monitoring acceleration to ensure that it is less than the maximum acceleration until the clutch engagement rate is greater than the set value.

[0023] The beneficial effect of adopting the above further scheme is that the method is simple, the design is reasonable, the minimum acceleration and maximum acceleration of the tractor are limited, and on the premise of improving vehicle driving comfort, the clutch slip time is shortened to the maximum extent during clutch control, thereby achieving the purpose of protecting the clutch.

[0024] Further, the S23 specifically includes:

[0025] In stage D, the pressure increases according to the set slope until it reaches the maximum pressure of the clutch.

[0026] The beneficial effects of adopting the above further solution are that the method is simple, the design is reasonable, the slip time of the clutch is shortened, and the purpose of protecting the clutch is achieved.

[0027] Further, the S3 specifically includes:

[0028] S31: In the E stage, the KP pressure is compensated in the interval H according to the gear interval of the power shift tractor and the load size;

[0029] S32: Stage F limits the maximum acceleration of power-shift tractors;

[0030] S33: G stage quickly presses the clutch.

[0031] The beneficial effect of adopting the above further scheme is that after the wet clutch is engaged, the effective parameters of the starting process are recorded, and combined with the percentage of the engine output torque, the control parameters of the gear shifting during driving are compensated, thereby improving the control accuracy and comfort of the starting and gear shifting process.

[0032] Further, the S31 specifically includes:

[0033] Based on the number of pressure changes during the starting phase and the engine torque after the clutch is fully engaged, the current vehicle load is estimated, and the pressure in the E phase is controlled according to the load size.

[0034] The beneficial effect of adopting the above further scheme is that in the E stage, according to the gear range and load size of the power shift tractor, the KP pressure is compensated in the range H, the power responsiveness of the vehicle during the gear shifting process is improved, and the ineffective slip of the clutch is avoided.

[0035] Further, the S32 specifically includes:

[0036] A maximum acceleration is selected by looking up the table and the maximum acceleration is limited until the clutch engagement rate exceeds the set threshold and enters the G stage.

[0037] The beneficial effect of adopting the above further solution is that the maximum acceleration of the power shift tractor is limited in the F stage, thereby improving the shift comfort.

[0038] Further, the S33 specifically includes:

[0039] The oil pressure increases rapidly to the maximum pressure of the clutch.

[0040] The beneficial effect of adopting the above further solution is that the clutch is quickly pressed in the G stage, thereby shortening the slipping time of the clutch.

[0041] Further, the S1 specifically includes:

[0042] The software system is used to change the current, collect the oil pressure and monitor the changes in the engine torque at the same time, until the engine torque exceeds the set threshold, and record the current current value and oil pressure value.

[0043] The beneficial effect of adopting the above further scheme is that the control method of the starting process, in which the A stage takes the starting speed as the target, increases the pressure rapidly, and improves the consistency of the response speed of the power shift tractor under different loads in different transmission ratio ranges. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 is a control flow chart of the present invention;

[0045] Figure 2 A control curve diagram for calibrating basic parameters of the tractor power converter in the present invention;

[0046] Figure 3 The present invention is a load-size automatic compensation shift curve diagram of the power shift tractor during the travel process. DETAILED DESCRIPTION

[0047] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0048] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0049] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0050] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0051] Example 1

[0052] like Figures 1 to 3 As shown, this embodiment provides a multi-mode clutch control method for a power shift tractor, comprising the following specific steps:

[0053] S1: Calibrate the basic parameters of the tractor wet clutch;

[0054] S2: Control the starting phase of the tractor;

[0055] S3: Control the gear shifting during the movement of the tractor.

[0056] This embodiment determines the current gear ratio and load size of the power shift tractor according to the parameters during the starting process of the power shift tractor, and compensates for the shifting process during driving, which can improve the control accuracy and comfort of the clutch curve of the vehicle starting and shifting during driving.

[0057] Example 2

[0058] On the basis of Example 1, in this embodiment, S2 specifically includes:

[0059] S21: Controlling the power shift tractor starting process, phase A;

[0060] S22: Controlling the power shift tractor acceleration limiting phases B and C;

[0061] S23: Control the power shift tractor pressure rapid increase stage D.

[0062] According to the starting KP point of the adaptive power-shift tractor, the transmission ratio range of the starting gear of the power-shift tractor is determined according to the relevant parameters of the KP point adaptive stage, thereby limiting the minimum acceleration and maximum acceleration of the tractor, and shortening the slip time of the clutch to the maximum extent during clutch control, thereby achieving the purpose of protecting the clutch.

[0063] Example 3

[0064] On the basis of Example 2, in this embodiment, S21 specifically includes:

[0065] According to the transmission parameter calculation, the oil pressure is increased by 1.5 bar every 890ms, and the vehicle speed signal is monitored. When the vehicle speed is greater than the set threshold (0.1km / h-0.5km / h), it jumps to stage B.

[0066] The method is simple and reasonably designed. It can adapt to the vehicle gear and load and estimate the vehicle load size based on process data to provide effective data for the subsequent control stage. On the premise of improving vehicle driving comfort, it achieves the goal of shortening the clutch slip time to the maximum extent during clutch control, thereby achieving the purpose of protecting the clutch.

[0067] Example 4

[0068] On the basis of any one of Embodiments 2 to 3, in this embodiment, S22 specifically includes:

[0069] Stage B is the acceleration stage, which controls the pressure to increase rapidly and reach the minimum acceleration (i.e. 0.6m / s 2 -3m / s 2 );

[0070] Phase C actively reduces the rate of pressure increase while monitoring acceleration to ensure that it is less than the maximum acceleration until the clutch engagement rate is greater than the set value (85%).

[0071] The method is simple and reasonably designed, and limits the minimum acceleration and maximum acceleration of the tractor. On the premise of improving the driving comfort of the vehicle, it shortens the slip time of the clutch to the maximum extent during clutch control, thereby achieving the purpose of protecting the clutch.

[0072] Example 5

[0073] On the basis of any one of Embodiments 2 to 4, in this embodiment, S23 specifically includes:

[0074] In stage D, the pressure increases at a set slope (i.e., 5 bar / s) until it reaches the maximum pressure of the clutch.

[0075] The method is simple and reasonably designed, and can shorten the slipping time of the clutch, thereby achieving the purpose of protecting the clutch.

[0076] Example 6

[0077] On the basis of the above embodiments, in this embodiment, S3 specifically includes:

[0078] S31: In the E stage, the KP pressure is compensated in the interval H according to the gear interval of the power shift tractor and the load size;

[0079] S32: Stage F limits the maximum acceleration of power-shift tractors;

[0080] S33: G stage quickly presses the clutch.

[0081] After the wet clutch is engaged, the effective parameters of the starting process are recorded, and combined with the percentage of engine output torque, the control parameters of the gear shifting during driving are compensated to improve the control accuracy and comfort of the starting and gear shifting processes.

[0082] Example 7

[0083] On the basis of Example 6, in this embodiment, S31 specifically includes:

[0084] Based on the number of pressure changes during the starting phase and the engine torque after the clutch is fully engaged, the current vehicle load is estimated, and the pressure in the E phase is controlled according to the load size.

[0085] In the E stage, the KP pressure is compensated in the H range according to the gear range of the power-shift tractor and the load size, so as to improve the power responsiveness of the vehicle during the gear shifting process and avoid the ineffective slip of the clutch.

[0086] Example 8

[0087] On the basis of any one of Embodiment 6 to Embodiment 7, in this embodiment, the S32 specifically includes:

[0088] Look up the table and select a maximum acceleration (i.e. 0.6m / s 2 -3 m / s 2 ), limiting the maximum acceleration until the clutch engagement rate exceeds the set threshold (85%) and then enters the G stage.

[0089] Stage F limits the maximum acceleration of power-shift tractors and improves shifting comfort.

[0090] Example 9

[0091] On the basis of any one of Embodiments 6 to 8, in this embodiment, S33 specifically includes:

[0092] The oil pressure increases rapidly to the maximum pressure of the clutch (i.e. 16 bar).

[0093] The G stage quickly compresses the clutch, shortening the clutch slip time.

[0094] Example 10

[0095] On the basis of the above embodiments, in this embodiment, S1 specifically includes:

[0096] The software system is used to change the current, collect the oil pressure and monitor the changes in the engine torque at the same time, until the engine torque exceeds the set threshold (100Nm), and record the current current value and oil pressure value.

[0097] The control method of the starting process takes the starting speed as the target in stage A, increases the pressure rapidly, and improves the consistency of the response speed of the power shift tractor under different loads in different transmission ratio ranges.

[0098] Based on the above scheme, the entire process is automatically controlled using the existing software system, with a high degree of automation, easy operation and high efficiency.

[0099] The present invention mainly includes maximum transmission ratio KP pressure learning, vehicle speed starting point pressure search, and automatic judgment of the acceleration limit range of the power shift tractor; after the wet clutch is engaged, the effective parameters in the starting process are recorded, and the control parameters of the shifting during driving are compensated in combination with the percentage of the engine output torque, so as to improve the control accuracy and comfort of the starting and shifting processes.

[0100] The specific steps of a multi-operating clutch control method for a power shift tractor provided by the present invention are as follows:

[0101] Use the software system to control the current (increase the current step by step), collect the oil pressure, monitor the change of the engine torque, and record the current current value and oil pressure value when the torque exceeds the set threshold;

[0102] Control the power shift tractor starting process in stage A. During the process, the control pressure increases according to a fixed time and a fixed pressure step. When the vehicle speed exceeds the set threshold (0.1-0.5km / h), it jumps to stage B. During the control process of stage A, the number of oil pressure increases is recorded;

[0103] B and C are acceleration limit stages. According to the number of oil pressure jumps in stage A, the more times, the higher the gear and the greater the load, the MAP table is checked. ACCT Automatically select target acceleration ACC T , used for control in stages B and C; the control pressure in stage B increases faster so that the power shift tractor acceleration quickly approaches the target value ACC T Then enter the C stage and look up the MAP table according to the number of pressure jumps ACCMAX , limit the maximum acceleration of the vehicle speed ACC MAX , after approaching the maximum acceleration limit threshold, the pressure is controlled to increase slowly, so that the vehicle speed increases linearly to meet the starting comfort. During the process, the engagement rate of the power shift tractor clutch is calculated. After the engagement rate reaches the set threshold, the pressure enters the rapid growth stage D, shortening the clutch slip time to achieve the purpose of protecting the clutch;

[0104] During the driving process, the gear shifting process combines the relevant parameters of the starting process and the engine torque after the clutch is fully engaged to determine the current load size of the power shift tractor, and automatically compensates the gear shift curve according to the load size of the power shift tractor (refer to the attached Figure 3 );

[0105] Phase E, based on the parameters recorded at the start of the power shift tractor and the engine torque after the clutch is fully engaged, look up the MAP table KP Calculate the control pressure of the E stage and compensate in the H pressure range. The E stage adopts a fixed time control method (entering the F stage after 800ms); after the timeout, enter the F stage and look up the MAP table according to the load size of the power shift tractorACCMAX , limit the maximum acceleration of the vehicle speed ACC MAX During the process, the clutch engagement rate is calculated; when the engagement rate exceeds the set threshold, it enters stage G, and the oil pressure increases rapidly to tighten the clutch.

[0106] The control method provided by the present invention has the following advantages:

[0107] The control method of the starting process is as follows: in stage A, the starting speed is taken as the target, and the pressure increases rapidly, which improves the consistency of the response speed of the power-shift tractor under different transmission ratio ranges and different loads; in stage B, the target acceleration ACCT is taken as the target according to the relevant parameters of stage A, which improves the response speed of the power-shift tractor; in stage C, the maximum acceleration is taken as the target according to the relevant parameters of stage A, which achieves the purpose of uniform acceleration of the power-shift tractor. During the clutch pressing process, when the engagement rate is greater than the set threshold, the pressure increases rapidly, shortening the slip time of the clutch. The entire control process improves the comfort of starting the power-shift tractor under different gear ranges and different load conditions, minimizes the clutch slip time, and achieves the purpose of protecting the clutch.

[0108] During the shifting process, the E stage compensates the KP pressure in the H range according to the gear range and load size of the power shift tractor, avoiding the ineffective slip of the clutch. The F stage limits the maximum acceleration of the power shift tractor, improving the shifting comfort. The G stage quickly compresses the clutch and shortens the clutch slip time. The entire control process improves the comfort of the tractor's shifting while driving. At the same time, according to the gear range and load compensation control method, the clutch slip time is shortened, achieving the purpose of protecting the clutch.

[0109] The existing power shift tractor control technology can adapt to the starting control under different engine loads with a fixed transmission ratio, but it has the disadvantage of being unable to adapt to the starting control under different transmission ratios and cannot meet the current driver's requirements for the driving comfort of power shift tractors.

[0110] The present invention mainly determines the starting gear transmission ratio interval range of the power shift tractor according to the starting KP point of the adaptive power shift tractor and the relevant parameters of the KP point adaptive stage, thereby limiting the minimum acceleration and the maximum acceleration of the tractor, shortening the clutch slip time to the maximum extent during clutch control, achieving the purpose of protecting the clutch, and limiting the maximum acceleration of the tractor, realizing a starting control method for the power shift tractor that adapts to different mechanical gears and different loads, and meeting the driving comfort of the tractor driver; according to the parameters in the starting process of the power shift tractor, the current gear transmission ratio and the load size of the power shift tractor are determined, and the shifting process during driving is compensated, which can improve the control accuracy and comfort of the shifting clutch curve during driving.

[0111] The present invention mainly proposes a method based on software control and acceleration closed-loop control to realize a control method for a power shift tractor to adapt to different mechanical gears, and is not limited by the engine horsepower range and is applicable to all.

[0112] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0113] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

[0114] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A multi-mode clutch control method for a power shift tractor, characterized in that: The specific steps include: S1: Calibrate the basic parameters of the tractor wet clutch; S2: Control the starting phase of the tractor; S3: Control the gear shifting during the movement of the tractor.

2. The multi-mode clutch control method for a power shift tractor according to claim 1, characterized in that: The S2 specifically includes: S21: Controlling the power shift tractor starting process, phase A; S22: Controlling the power shift tractor acceleration limiting phases B and C; S23: Control the power shift tractor pressure rapid increase stage D.

3. The multi-mode clutch control method for a power shift tractor according to claim 2, characterized in that: The S21 specifically includes: According to the transmission parameter calculation, the oil pressure is increased by 1.5 bar every 890ms, and the vehicle speed signal is monitored. When the vehicle speed exceeds the set threshold, it jumps to stage B.

4. The multi-mode clutch control method for a power shift tractor according to claim 2, characterized in that: The S22 specifically includes: Stage B is the acceleration stage, in which the control pressure increases rapidly to reach the minimum acceleration; Phase C actively reduces the rate of pressure increase while monitoring acceleration to ensure that it is less than the maximum acceleration until the clutch engagement rate is greater than the set value.

5. The multi-mode clutch control method for a power shift tractor according to claim 2, characterized in that: The S23 specifically includes: In stage D, the pressure increases according to the set slope until it reaches the maximum pressure of the clutch.

6. The multi-mode clutch control method for a power shift tractor according to any one of claims 1 to 5, characterized in that: The S3 specifically includes: S31: In the E stage, the KP pressure is compensated in the interval H according to the gear interval of the power shift tractor and the load size; S32: Stage F limits the maximum acceleration of power-shift tractors; S33: G stage quickly presses the clutch.

7. The multi-mode clutch control method for a power shift tractor according to claim 6, characterized in that: The S31 specifically includes: Based on the number of pressure changes during the starting phase and the engine torque after the clutch is fully engaged, the current vehicle load is estimated, and the pressure in the E phase is controlled according to the load size.

8. The multi-mode clutch control method for a power shift tractor according to claim 6, characterized in that: The S32 specifically includes: A maximum acceleration is selected by looking up the table and the maximum acceleration is limited until the clutch engagement rate exceeds the set threshold and enters the G stage.

9. The multi-mode clutch control method for a power shift tractor according to claim 6, characterized in that: The S33 specifically includes: The oil pressure increases rapidly to the maximum pressure of the clutch.

10. The multi-mode clutch control method for a power shift tractor according to any one of claims 1 to 5, characterized in that: The S1 specifically includes: The software system is used to change the current, collect the oil pressure and monitor the changes in the engine torque at the same time, until the engine torque exceeds the set threshold, and record the current current value and oil pressure value.

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